Improvement in artificial legs



@einen tatrefatmt @Hire ALBERT STRASSER, OF MONTGOMERYfALABAMA.

Letters Patent No. 76,267, dated March 31, 1868.

IMPROVEMENT IN ARTIFICIAL LEGS.

TO ALL WI-IOM IT MAY CONCERN z Bc it known `that I, ALBERT STRASSER, ofv Montgomery, in the county of Montgomery, and Stateof Ala'- hama, have invented new and useful Improvements in Artificial Legs; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part ofA this specification. v

The present invention relates to artificial legs when the leg is amputated ator above the knee. Heretofore, in all artificial legs in such cases of amputation, there has been a great liability of the leg bending forward quickly at the knee, with nothing to prevent the-same except the backward pressure of the Astump on the artificial leg, which, requiring great leverage, was oftentimes injurious to the stump. It was also almost impossible'for any person with 'a short stump to use 'an artificial' leg as hitherto made, as such legs required the whole weight of the body to be brought forward inorder to keep the leg from forward motion at the knee-joint, consequently producing an awkward stiffness in the walk, and also danger of falling.

By the construction of the artificial leg embraced in the present inventionall the above disadvantages are overcome, as will be obvious from the followingdetail description thereof, reference being had to the accompanying plate of drawings, in which- Figure 1 is a transverse vertical section of an artificial leg made according to the presen-t invention, and

Figure 2 a central vertical section, taken in the plane of the line wir, iig. l.

A, in the drawings, represents -the part or section of the artificial leg which is designed to receive the stump, B the knee-joint, and C the part f the leg below 'the knee-joint, to .the lower end of which the footD is hung or hinged. The two parts A and C of the leg, are, by their respective frames E and F, hinged or jointed together with a stop-joint, G, bywhich the distance to which they can turn or swing, the one upon the other, 1s regulated and limited. H, a frame, arranged to slide by its two arms, I, in suitable grooves or ways of the frame to the part C of the leg below the knee, and b y its stem J, passing through-the cross-bar Kof the frame F, connected hy its string --L to the rear portion of the foot tothe leg. N, a spiral or coiled spring around stem J to frame I-I, by'means of which such frame is made `to engage with the notches O of the frame, carrying the upper part Aiof the leg, which notches are in positioasuitable to hold the two parts of the leg when straightened out or in line'withl each other. By the stop-joint at the knee for the connection with the fo0t,the

leg is allowed to bend only when itis required, and without'.- any pressure of stump, and the leg cannot bendV until the weight of the body comes upon the toe or front portion of the foot. For regulating the action of the sliding frame in the part ofv the leg, .the eye-bolt- T, to which it is secured in the foot, is passed through the heel of the same, and there secured by a screw-nut, U, by means'of which, such eye-bolt fraction can be shortened or lengthened at pleasure. ,V, elastic India-rubber or other suitable cushions interposed between the part C of the leg and the foot, by means ofwhich the motion ofthe sliding frame is rendered more accurate, and theileg given an elastic and natural motion.

I claiin as new, and desire to secure by Letters Patent- The combination of the frames E F, hinged together with the stop-joint G, the sliding frame Il, having arms I engaging' with the notch-es O of the frame E, the cross-har K, stem J, `spiral spring N, strap L, and adjustable eye-.bolt T, all constructed and arranged to operate as herein described for the purpose specified.

' ALBERT sTRAssER.

llfitncsses:

I. E. ROBERTS, P. PETERSON. 

